Production of alcohols



Patented Oct. 24, 1933 PRODUCTION OF ALCOHOLS Martin Luther, Mannheim,

and Wilhelm Dietrich, oppau, Germany, assignors to L G. FarbenindustrieAktiengesellschait, Frankforton-the-Main, Germany N Drawing.

Application October 3, 1930, Serial No. 486,281, and in Germany October15,

5 Claims. (01. 260-156) The present invention relates to the productionof alcohols.

It is already known that the oxidation of hydrocarbons may be carriedout for example by 5 treating the initial materials in the liquid phasewith air or other gaseous oxidizing agents in the presence of alkali orsolutions of alkali. In this manner the oxidation proceeds with theinformation of acids and at least some portion of the acids is obtainedin the form of their salts,

We have now found that alcohols are mainly obtained in the oxidation ofdifiicultly volatile, i. e. from liquid to solid, hydrocarbons having aboiling point of above 180 C. by adding at least 2 per cent by weight,calculated with reference to the initial materials, of non-gaseous i. e.fromliquid to solid acids having a dissociation constant between 10* and10', to the hydrocarbons to be oxidized with the aid of oxygen, air orother gaseous oxidizing agents containing free oxygen such as mixturesof oxygen with carbon dioxide or nitrogen or air diluted by inert gasessuch as carbon dioxide, nitrogen and the like. As suitable acidsaccording to the definition given above may be mentioned in particularorganic acids of low molecular weight, as for example formic acid,acetic acid, propionic acid, maleic acid, benzoic acid and the like.Weak inorganic acids such as boric acid or its anhydride, antimonypentoxide, stannic acid and the like may also be employed. '.;S incewater is immediately formed in the oxidation, the anhydrides of theaforesaid acids may be "employed, which are immediately converted intothe acids and are therefore considered as equivalents to the acids andcomprised within the term acids. These additions which apparentlyinterrupt and prevent the oxidation from proceeding beyond the alcoholstage of oxidation and render the products more uni- 40 form, areemployed in large amounts, at least 2 per cent calculated with referenceto the hydrocarbons to be oxidized, and the addition may be effected inany suitable manner, the best results being generally obtained withquantities of from 5 5 to 10 per cent, the yields being graduallydecreased'with higher quantities of acid. For example the current of gasto be oxidized may be laden with the vapours of the acids and the likebefore its entry into the oxidizing chamber, or the acids and the likemay be added all at once or in consecutive fractions to the hydrocarbonsto be oxidized. The duration and reaction temperature of the processdepend on the initial materials but in most cases blowing with thegaseous oxidizing agent for from 2 to 3 hours at temperatures betweenabout 100 and 2G0 C. isv sufiicient.

The operation is stopped as soon as a sample shows a saponiilcationvalue of 70, the reac tion being not allowed to proceed further "sinceotherwise a too far reaching oxidation antidestruction would occur.. Therecovery of the acids,

which are partly contained in the vapour phase in the gases leaving thereaction vessel, may be carried out in any suitable manner, as forexample by boiling up under a reflux condenser together with water or bywashing out and the like.

Aliphatic hydrocarbons, as for example petroleum fractions such asmiddle oils, parafiins,

ceresine and the like or naphthene hydrocarbons,

such as are contained in certain paraiiin oil, gas

oil and the like or synthetic hydrocarbons, as for example hydrocarbonsobtained by the hydrogenation of tars and the like are especially suitable as initial materials forthe process according to the presentinvention. The oxidation of the initial materials may be carried outatat mospheric or higher pressures, such asup to 100 atmospheres ifliquid initial materials are em-' ployed, whereas pressures up to 50atmospheres are usually sufficient on working with solid initialmaterials. The reaction is preferably accelerated,

in the manner already known, by the presence of catalysts such asnaphthenates or resinates,

whereby, in combination with the said additions of acids and the like,the formation of alcohols is still further promoted.

The reaction products, which besides unattacked initial material andacid constituents mainly consist of free alcohols and esters thereof,

are separated in the manner already known as for example by extractionwith organic solvents, as for example ethyl alcohol, or crystallization.after removal of the acid constituents. The alcohols thus obtained areliquid or solid according to the nature of the initial materials empyed.

The following examples will further illustrate the nature of thisinvention, but the invention is not restricted to these examples. Theparts are by weight.

Example 1 I Hard paraflin wax is fused and heated to v 160 C. and foreach kilogram of the wax 1 cubic metre of air, which has been laden with22 grams of acetic acid by passing it at 18 C. through a vessel filledwith concentrated acetic acid, is blown per hour through the heated wax.After 8 hours a pale coloured oxidation product is obtained containing40 per cent by weight calculated with reference to the initial materialof alcohols.

Example 2 Hard paraflin wax is fused and heated to 175 C. and for eachkilogram of the wax 50 grams of'boric anhydride are added and 1 cubicmetre of air, which has been 'laden with 16 grams of acetic acid bypassing it at 15 C. through a vessel filled with concentrated aceticacid, is blown per hour through the heated wax. After 3 hours a palecoloured oxidation product is obtained containing 44 per-cent by weightcalculated with reference to the initial material of alcohols.

Example 3 A fraction of Pennsylvania crude mineral oil boiling between180 and 350 C. is mixed with 1 per cent of its weight of manganesenaphthenate and air is blown through at 160 C. at the rate of 1 cubicmetre per hour and per kilogram of the oil, the air having been ladenwith 37 grams of acetic acid per. each cubic metre before itsintroduction into the reaction vessel by passing it at 20 C. through avessel filled with concentrated acetic acid. After 3 hours an oxidationproduct is obtained which contains 35 per cent calculated with referenceto the initial material of alcohols. When working without acetic acidabout of the said yield of alcohols is obtained.

Erample'4 800 parts of molten hard paraflin wax are incorporated with 16parts of benzoic anhydride and the whole is blown with air at 160 C. ata velocity of 1 cubic metrev of air per hour and per each kilogram ofthe wax., In the course of two hours further 10 parts of benzoicanhydride are added and blowing is stopped after two and a half hours.The yield of reaction product is 106 per 'cent by weight of theinitialmaterial. After separating on" unsaponiflable material (esters, lactonesand free acids) 75 per cent of the whole oxidation product of neutralproducts is obtained, which possess a hydroxyl value of 84.3.

' Example 5 1000 parts of American hard parailin wax are incorporatedwith 50 parts of antimony pentoxide and then blown with air at180 C. ata velocity of 1 cubic metre per hour and per each kilogram Example 6 100parts of a fraction of crude Pemisylvania mineral oil boiling between180 and 350 C. are blown with air at 160 C. at a velocity of 1 cubicmetre per hour and per 1 kilogram of the oil" after the addition of 1part of manganese naphthenate. Before entering the oxidation vessel thecurrent of air passes a vessel filled with concentrated acetic acid thetemperature of which After separating oflf un'-- is kept at 20 C. sothat each cubic metre of, air contains 37 grams of acetic acid. After 3hours blowing, an oxidation product is obtained which contains about 35parts of alcohols.

What we claim is:-

1, In the liquid'phase oxidation of diificultly volatile non-aromatichydrocarbons boiling above 180 C. with gaseous oxidizing agents whileheating at atmospheric pressure, the step which comprises carrying outthe oxidation from the start in the presence of an added organic acidhaving a dissociation constant between 10 and 10 the'quantity of theorganic acid added during the whole reaction being at least 2 per centby weight of the initial hydrocarbons and the reaction being stopped atleast as soon as the saponification value of the reaction product is 70.

2. In the liquid phase oxidation of difficultly volatile non-aromatichydrocarbons boiling above 180 C. with gaseous oxidizing agents whileheating. to a temperature between about 100 and 200 C. at atmosphericpressure, the step which comprises carrying out the oxidation from thestart in the presence of an added organic acid having a dissociationconstant between 10 and 10- the quantity of the organic acid addedduring the whole reaction being about from 2 to 10 per cent by weight ofthe initial hydrocarbons and the reaction being stopped at least as soonas the saponification value of the reaction product is '70.

3. In the liquid phase oxidation of difhcultly volatile non-aromatichydrocarbons boiling above 180 C. withairwhile heating to a, temperaturebetween 100 and 200 C. at atmospheric pressure, the step which comprisescarrying out the oxidation from the start in the presence of an addedorganic acid having a dissociation constant between 10- and 10*, thequantity of the organic acid added during the whole reaction being from5 to 10 per cent by weight of the initial hydrocarbons and the reactionbeing stopped at least as soon as the saponification value of thereaction product is '70.

4. In the liquid phase oxidation of a parafiin boiling above 180 C.with-air while heating to a temperature between 100 and 200 C. atatmospheric pressure, the step which comprises carry-' ing out theoxidation from the start in the presence of an added organic acid havinga dis sociation constant between 10" and 10 the quantity of the organicacid added during the whole reaction being from 5 to 10 per cent byweight of the initial paramn and the reaction being stopped at least assoon as the saponification value of the reaction product is '70.

5. In the liquid phase oxidation of a liquid paraffin boiling above 180C. with air while heating to a temperature between 100 and 200 C.

at atmospheric pressure, the step which comprises carrying out theoxidation from the start in the presence of added acetic acid, thequantity of acid added during the whole reaction being from 5 to 10 percent by weight of the initial paraffin and the reaction being stopped atleast as soon as thesaponification value of the reaction product is 70.

MARTIN LUTHER. WlLHELM DIETRICH.

